tear vs tear down

tear is a noun but tear down is not a noun.

Word	Noun	Adjective	Verb	Adverb
tear	Yes	No	Yes	No
tear down	No	No	Yes	No

tear (noun)	tear down (noun)
a drop of the clear salty saline solution secreted by the lacrimal glands
the act of tearing
an occasion for excessive eating or drinking
an opening made forcibly as by pulling apart

tear (verb)	tear down (verb)
separate or cause to separate abruptly	tear down so as to make flat with the ground
to separate or be separated by force
strip of feathers
move quickly and violently
fill with tears or shed tears